911, Reims-Gueux
The sad story of the circuit de Reims (now a public road):
Reims-Gueux was a triangular motor racing road course near Reims, France, which hosted 14 French Grands Prix.
Reims-Gueux was first established in 1926 on the public roads between the small French villages of Thillois and Gueux. The circuit had two very long straights between the towns, and teams strove to maximize straight-line speed of their cars; many slipstream battles ensued. Race organizers actually felled trees and demolished old houses in order to make the circuit even quicker. In 1952, the circuit was significantly altered to bypass the village of Gueux, and many people now refer to the course as simply Reims.
Its first event was the Grand Prix de la Marne, staged by the Automobile Club of Champagne. International racing came soon thereafter, with the first official Formula One event occurring in 1950, the inaugural year of the Formula One world championship. The circuit was last used by Formula One in 1966, and it closed permanently in 1972 due to financial difficulties.
In 1997, there was to be a historic race held there, but for technical reasons, it was cancelled several months before it was due to take place and in 2002, the bulldozers arrived to demolish some portions of the track. Sections of the track around the pit lanes are still visible today.
Les Amis du Circuit de Gueux is a non-profit organisation working to preserve traces of the circuit (source).
More here (very comprehensive): REIMS: THE HOME OF SLIPSTREAMING
(911 images: Suggs— wonderful as always)
Motoring Con Brio 
although no longer operating as a race track, it can (and was) much worse prior to the most recent restoration efforts:
motoringconbrio said this on August 30, 2011 at 5:12 pm
Fantastic history here! Thanks for sharing the links!
Larry said this on August 30, 2011 at 5:43 pm